Copy missing values from INIT_CFG to config_db during db_migration (s…

…onic-net#1522)

FEATURE table is a part of 201911 image database, but absent in 201811 images. The warm upgrade from 201811 image to 201911 image fails as the feature table is missing in the DB and multiple errors are seen in syslog.

This PR fixes DB_MIGRATOR code to update missing init_cfg tables into config_db.

config/main.py

@@ -838,7 +838,7 @@ def reload(filename, yes, load_sysinfo, no_service_restart):
         log.log_info("'reload' stopping services...")
         _stop_services()
 
-    # In Single AISC platforms we have single DB service. In multi-ASIC platforms we have a global DB
+    # In Single ASIC platforms we have single DB service. In multi-ASIC platforms we have a global DB
     # service running in the host + DB services running in each ASIC namespace created per ASIC.
     # In the below logic, we get all namespaces in this platform and add an empty namespace ''
     # denoting the current namespace which we are in ( the linux host )

scripts/db_migrator.py

@@ -2,6 +2,7 @@
 
 import os
 import argparse
+import json
 import sys
 import traceback
 
@@ -19,7 +20,7 @@
 except KeyError:
     pass
 
-
+INIT_CFG_FILE = '/etc/sonic/init_cfg.json'
 SYSLOG_IDENTIFIER = 'db_migrator'
 
 # Global logger instance
@@ -254,6 +255,24 @@ def set_version(self, version=None):
         self.configDB.set_entry(self.TABLE_NAME, self.TABLE_KEY, entry)
 
 
+    def common_migration_ops(self):
+        try:
+            with open(INIT_CFG_FILE) as f:
+                init_db = json.load(f)
+        except Exception as e:
+            raise Exception(str(e))
+
+        for init_cfg_table, table_val in init_db.items():
+            data = self.configDB.get_table(init_cfg_table)
+            if data:
+                # Ignore overriding the values that pre-exist in configDB
+                continue
+            log.log_info("Migrating table {} from INIT_CFG to config_db".format(init_cfg_table))
+            # Update all tables that do not exist in configDB but are present in INIT_CFG
+            for init_table_key, init_table_val in table_val.items():
+                self.configDB.set_entry(init_cfg_table, init_table_key, init_table_val)
+
+
     def migrate(self):
         version = self.get_version()
         log.log_info('Upgrading from version ' + version)
@@ -262,6 +281,8 @@ def migrate(self):
             if next_version == version:
                 raise Exception('Version migrate from %s stuck in same version' % version)
             version = next_version
+        # Perform common migration ops
+        self.common_migration_ops()
 
 
 def main():

sonic-utilities-tests/db_migrator_test.py

@@ -1,3 +1,4 @@
+import mock
 import os
 import pytest
 import sys
@@ -61,12 +62,13 @@ def test_mellanox_buffer_migrator_negative_cold_reboot(self, scenario):
         db_after_migrate = scenario + '-expected'
         device_info.get_sonic_version_info = get_sonic_version_info_mlnx
         _ = self.mock_dedicated_config_db(db_before_migrate)
-        import db_migrator
-        dbmgtr = db_migrator.DBMigrator(None)
-        dbmgtr.migrate()
-        expected_db = self.mock_dedicated_config_db(db_after_migrate)
-        self.check_config_db(dbmgtr.configDB, expected_db.cfgdb)
-        assert not dbmgtr.mellanox_buffer_migrator.is_buffer_config_default
+        with mock.patch("db_migrator.DBMigrator.common_migration_ops"):
+            import db_migrator
+            dbmgtr = db_migrator.DBMigrator(None)
+            dbmgtr.migrate()
+            expected_db = self.mock_dedicated_config_db(db_after_migrate)
+            self.check_config_db(dbmgtr.configDB, expected_db.cfgdb)
+            assert not dbmgtr.mellanox_buffer_migrator.is_buffer_config_default
 
     @pytest.mark.parametrize('sku_version',
                              [('ACS-MSN2700', 'version_1_0_1'),
@@ -97,10 +99,11 @@ def test_mellanox_buffer_migrator_for_cold_reboot(self, sku_version, topo):
         # migration from any version between start_version and the current version (inclusive) to the current version will be verified
         for version in self.version_list[start_index:]:
             _ = self.mock_dedicated_config_db(self.make_db_name_by_sku_topo_version(sku, topo, version))
-            import db_migrator
-            dbmgtr = db_migrator.DBMigrator(None)
-            dbmgtr.migrate()
-            self.check_config_db(dbmgtr.configDB, expected_db.cfgdb)
-            assert dbmgtr.mellanox_buffer_migrator.is_buffer_config_default
+            with mock.patch("db_migrator.DBMigrator.common_migration_ops"):
+                import db_migrator
+                dbmgtr = db_migrator.DBMigrator(None)
+                dbmgtr.migrate()
+                self.check_config_db(dbmgtr.configDB, expected_db.cfgdb)
+                assert dbmgtr.mellanox_buffer_migrator.is_buffer_config_default
 
         self.clear_dedicated_mock_dbs()